648 On the Method of judging by the Ear 
knows the true place of the speaker, because his 
voice is the prevailing sound at the time. But 
were it possible to prevent his words from reach- 
ing any one of the audience directly, what then 
would follow? Undoubtedly a complete ease of 
ventriloquism would be the consequence, and 
the person so circumstanced would transport the 
orator, in his own mind, to the place of the prin- 
cipal echo, which would perform the part of the 
prevailing sound at the instant. This he would 
be obliged to do, because the human judgment 
is bound, by the dictates of experience, to regard 
the person as inseparable from the voice; and 
the deception in question would be unavoidable, 
heing produced by the same concurrence of causes 
which makes a peal of bells, situated in a valley, 
seem to change place in the opinion of a traveller. 
Tt is the business of a ventriloquist to amuse his 
admirers with tricks resembling the foregoing 
delusion; and it will be readily granted, that he 
has a subtle sense, highly corrected by experience, 
to manage, on which account the judgment must 
be cheated as well as the ear. | This can only be 
accomplished by making the pulses, constituting 
his words, strike the heads of his hearers, not in 
the right lines that join their persons and his, 
He must therefore know how to disguise the true 
direction of his-voice, because the artifice will 
give him an opportunity to substitute almost any 
